GB1382018A - Dual frequency array - Google Patents

Abstract

1382018 Aerials WESTINGHOUSE ELECTRIC CORP 11 July 1973 [4 Aug 1972] 33016/73 Heading H4A An aerial arrangement for operation in a first higher and in a second lower frequency band (e.g., 9 to 10 GHz and 1À8 to 2 GHz) comprises a plurality of array elements each including an opening 46, Fig. 5, in a conductive strip 44 and an open waveguide portion, having side walls 45, 47, with an element 48 (monopole or dipole) transversely disposed therein. Radiation due to the opening 46 is in the first frequency band, and is horizontally polarized. Radiation due to the element 48 is in the second frequency band, and is vertically polarized. Further decoupling between the radiating elements is provided by spacing the side walls 45, 47 sufficiently close together so that the cut-off frequency of the waveguide is higher than the highest frequency of the first frequency band. As shown in side view in Fig. 2, in which the conductive strip is referenced 20, the opening 22, the side walls 16, 17, and the transverse radiator 24, the latter is a monopole located approximately below the opening. It extends upwardly from the wall 17 into a hole in the wall 16, and the conductors of a feed line are connected to the upper end of the monopole and to the rim of said hole (Fig. 3, not shown). In a dipole arrangement, tubular and cylindrical members extend respectively from the walls 16, 17 towards the centre of the waveguide (Fig. 4, not shown). The waveguide has an end wall 26 which is so spaced from the element 24 that all radiation is directed outwardly. All array elements may be individually fed, in both frequency bands.